A dishwasher in the related art has a spray arm with a series of spray apertures, water at high pressure sprayed through the spray apertures can flush dishes to clean the dishes. In order to reduce water consumption, there are a limited number of spray apertures, and each spray aperture can only sprays water to one direction, resulting in a limited spraying area of the whole spray arm, and a lot of areas cannot be directly flushed, which means in order to achieve a cleaning effect, a long washing time is needed, reflection of a water flow and probability of reflection need improving. The spray arm of the dishwasher in the related art consumes a long washing time and has dead areas where dishes cannot be cleaned during the washing.